This system includes a 20 foot pylon with an AZ/EL “top hat” positioner, plus the base includes pylon-side-shift, pylon-rotate, and pylon-tilt-down capability. One of the design requirements on this project was that the pre-existing foam column and its positioner could not be affected by the new pylon system. The system has the ability to side-shift the pylon +/- 3 feet so that very large targets can be tested by moving the target area of interest into the quiet zone.
The covers over the pit that allowed the side-shift had to be flush with the floor and allow a forklift to drive on them without failing.
The system can also rotate the pylon 180 degrees so that the pylon faced the back of the chamber for target mount and dismount. This minimized the impact on absorber on the chamber floor (the bare floor area is well behind the target area).
When the foam column is in use the pylon tilts down into an aft-facing trench in the floor. Doors automatically open and close before and after this maneuver. These doors also required that a forklift could drive across them.